At TBRHSC: 15 randomly selected participants from each group will undergo whole brain functional MRI (fMRI) imaging by a member of the research team at TBRHSC. The scans will include a resting state fMRI, an 8 minute scan during alternating 30 second on, 30 second off evoked pressure pain stimulus, a T1 high resolution anatomical image, and a diffusion tensor image. Please see the attached grant proposal for details regarding this imaging method.